Timer device



H. ROVIN TIMER DEVICE Sept. 4,Y 1962 2 Sheets-Sheet 1 Filed Aug. 26, 1960 o INVENTOR. HERMAN RovlN ATTORNEY Sept 4, 1962 H. RovlN 3,052,162

TIMER DEVICE:

Filed Aug. 26, 1960 2 sheets-sheet 2 AT T 3,5Z,l62 Patented Sept. 4, 1962 3,052,162 TIMER DEVICE Herman Rovira, Valley Stream, NX., assigner, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed Aug. 26, 1960, Ser. No. 52,314 10 Claims. (Cl. 89-65) This invention relates to missiles, and more particularly to apparatus Ifor initiating an event in a missile upon lapse of a definite interval of time after the missile is launched.

In some missile systems it is desirable to initiate an event in a missile upon lapse of a deiinite interval of time after missile launching as determined lby a remotely located iire control device of the type which generates a continuously varying order signal for controlling the interval of time. Examples of such systems are shown in co-pending U.S. patent iapplications Serial No. 790,976 led February 3, 1959, now U.S. Patent No. 3,001,339, and Serial No. 816,008 tiled May 23, 1959, each of which discloses a missile system wherein a missile travels along a predetermined ballistic trajectory until, upon lapse of a desired interval of time after launching, an explosive element carried by the missiles is detonated initiating certain missile retarding effects which cause the missiles to depart from such trajectory. An example of a missile launching apparatus for -use in such missile system is shown in co-pending application Serial No. 817,951, led June 3, 1959, now U.S. Patent No. 2,960,009.

One of the objects of the present invention is to provide apparatus for initiating an event in a Amissile upon lapse of a definite interval of time after missile launching and with which such interval of time may be selectively varied as desired up to the instant the missile is launched.

Another object is to provide apparatus as aforesaid with which such interval of time may be automatically varied :by a remotely located lire control device of the type which provides a continuously varying signal for controlling such interval.

Another object is to provide apparatus of the aforesaid type which incorporates inexpensive parts which are easy to manufacture and which has a high degree of accuracy.

Other objects `and many of the `'attendant advantages of this invention will be readily appreciated as the same become better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:

FIG. l is a schematic diagram of the apparatus comprising the present invention;

FIG. 2 is a side elevation, partially broken away, of an assembly containing certain of the components of the apparatus of FIG. 1;

FIG. 3 is a section taken along line 3 3 of FIG. 2;

FIG. 4 is a section taken along line 4 4 of FIG. 2;

FIG. 5 is a section taken along line 5 5 of FIG. 2; and

FIG. 6 is an enlarged view of a detail indicated by arrow 6, FIG. 2.

Referring in detail to the drawing and particularly FIG. l, the invention comprises, in general, apparatus for initiating an event in a missile upon lapse of a definite interval of time, which may be employed with various missile launching arrangements, such las the launching arrangement illustrated which generally includes a missile 10, which is to be launched from a missile launcher 12, carried by a ship 14, and various components disposed in the ship and the missile. A tire control device l16 for controlling the interval of time between the instant the missile is launched vand the detonation of an electrically ignited explosive element 18 carried by missile 10 generates a continuously varying order signal for controlling such interval, which signal is in the form of an angular position of a rotatable output shaft 20. Explosive element 18 may, 'for example, be the explosive unit 64 disclosed in copending application Serial No. 790,976, now U.S. Patent No. 3,001,339, hereinbefore referred to, or the explosive block 76 disclosed in copending application Serial No. 816,008 hereinbefore referred to.

An electrical breakaway connector assembly 22 comprising :a multiple socket member 24 aflxed to missile 10, and a multiple prong member 26 aixed to missile launcher 12, establishes electrical communication between components within ship 14 and components within missile before the missile is launched. Upon launching, multiple socket member 24 separates from multiple prong member 26 severing such electrical communication. Multiple prong member 26 may, for example be multiple prong timer plugs 376 disclosed in copending application Serial No. 817,951, now U.S. Patent No. 2,960,009, hereinbefore referred to.

A clock-motor mechanism 28 having a rotatable clockmotor shaft 38 projecting from one of its ends is mounted to a frame 32 which is carried by the missile. As seen in FIGS. 2 and 6, clockmotor 28 includes a housing assembly attached to frame 32, which housing assembly comprises a journal element 34 disposed adjacent an upstanding portion of lframe 32, an `annular disk 36 disposed adjacent journal element 34 which disk Ihas a limit stop 38 formed thereon, as best shown in FIG. 5, and a subfframe disposed adjacent disk 36 comprising side plates 42 and 44 secured together in spaced parallel relation- Iship, `all suitably fastened together. Journal element 34 has a central aperture 46 in which clockmotor shaft 30 is journaled. Clockmotor shaft 30 extends into the aforesaid housing assembly and has a disk portion 48 formed thereon which carries lug 50, FIG. 5, engageable with limit stop 38, and has a threaded portion 52 formed thereon which extends through an aperture in side plate 42 into the escapement subframe with its end pivotally 'mounted to side plate 44. Clockmotor shaft 30 projects `from journal element 34 land constitutes an operating shaft of the `clockmotor mechanism. Clockmotor shaft 30 is rotatable between the limit stop positions established by limit stop 38, and lug 50, and is shown in its limit stop position in the direction of arrow A. Clockmotor shaft 30 is resiliently urged to rotate in the direction of arrow A by a spiral lwound hat spring 54 disposed in a cavity S6 formed in journal element 34 which spring has one of its ends fastened to journal element 34 and the other fastened to the clockmotor shaft. Within the aforesaid subframe is a clockwork mechanism comprising a step-up `gear train 58 rotatably mounted between side plates 42, 44, which gear train drives a conventional oscillating vpallet: type escapement, not shown. As best shown in FIG. 6, clockmotor shaft 30 is drivingly connected to the escapement mechanism through a friction clutch subassernbly 60 comprising a cup-shaped element 62 having a icentra-l aperture extending therethrough, which cup- 60 shaped element is resiliently urged :against side face 64 of disk portion 48 with sufficient force to provide `a frictionally engaging relationship between cup-shaped element 62 and -face 64 by a resilient dome washer 66 and a nut 68 which threadedly engages threaded portion 52 of the clockmotor shaft, cup-shaped element 62 having a ring gear 70 formed on its outer surface which enmeshes ya rst pinion 72 of gear train 58, which gear train in turn drives the escapement mechanism. The angular position of clockmotor shaft 30 may be varied as desired 70 independent of the escapement mechanism in response to suitable external forces applied to the clockmotor shaft, friction clutch lassembly 60 being adapted to slip in response to a force in excess of a predetermined magnitude applied to clockmotor shaft 3i) against the retarding effects of the escapement mechanism. The escapement mechanism is chosen to govern the rate of rotation of shaft 30 `when it is rotated in response to the force of spring 54. Clockmotor mechanism 28` is operated by positioning shaft 30 away from its limit stop position in the direction of arrow A, and when desired, removing the positioning forces applied to the shaft. Upon removal f such forces spring S4 drives clockmotor shaft 30 in the direction of arrow A at a rate of rotation determined by the escapement mechanism. Accordingly, clockmotor mechanism 28 produces a biasing effect, biasing clockmotor shaft 30 to rotate in the direction of arrow A at a predetermined rate of rotation.

A particular angular position Vof clockmotor shaft 28 about its axis is established as a reference switch closing position by a switch device 74 which comprises a rotor assembly mounted to clockmotor shaft 30 for rotation therewith, and :a wiper assembly mounted on fname 32. The rotor assembly includes a disk-shaped element 80, FIGS. 2 and 3, of an electrical insulating material and an electrically conductive segment S2 iixedly inlaid into a face 84 of the rotor. The wiper assembly includes a pair of wipers 86, 88 mounted on an insulating element 90 fixed on frame 32, and electrically connected to a pair of terminals 92, 94 respectively. Wipers 86, 88 are of resilient metal, each having a contact point formed thereon and each being so arranged that the contact point is resiliently urged against face 84 of element 80 in the path of segment 82. Segment 82 electrically connects wipers 86, S8 when it is in its phantom line position shown in FIG. 3, establishing such position as a reference circuit closing position. As will become apparent, clockmotor shaft 30 is moved between various angular positions away from such reference position in a direction opposite to arrow A against the biasing effect of the clockmotor mechanism prior to missile launching by the application of suitable external forces thereto and such external forces are removed from shaft 30 at the instant the missile is launched thereby initiating rotation of clockmotor shaft 30 in response to the biasing effect of the clockmotor mechanism at the instant the missile is launched. The clockmotor mechanism rotates clockmotor shaft 30 in the direction of arrow A at a constant rate of rotation effecting a switch closing action upon final movement of segment 80 -to its phantom line position. Since clockmotor shaft 30 rotates at a predetermined rate of rotation, the interval of time between the instant the missile is launched and the instant such switch closing action is effected is determined by the angular position of Shaft 30 for rotation therewith to sense its angular position. Resistance element 106 and resistance element 110 are connected in parallel by leads 114, 114, which electrically communicate through breakaway connector 22, such resistance elements constituting the legs of a bridge network. A power source 116 is applied across the ends of the bridge network through leads 118, 118. In accordance with well known principles such network constitutes a normally balanced bridge type error sensing network for comparing the angular position of shaft 20 of the fire control device and clockmotor shaft 30 and chosen to generate an error signal in the `for-m of an electrical voltage between wiper arm 1tl8 and wiper arm 112 in accordance with the departure of the actual position of clockmotor shaft 30 from the aforesaid position in accordance with the fire control device. Such error signal is fed to servo amplifier 102 through a lead 120 between wiper arm 108 and input terminal 122 of servo amplifier 102, and through a lead 124 between wiper arm 112 and an input terminal 126, which lead 124 electrically communicates through electrical breakaway connector 22. Servo amplifier 102 amplifies the error signal providing an amplied error signal at its output terminals 128 for energizing servomotor 194, which is fed thereto through a cable 13A? between output terminals 128 and input terminals 132 of servomotor 11M, which cable also electrically communicates through breakaway connector 22. A reduction gear assembly 134 is fastened at one of its ends to an upstanding portion of frame 32 and servomotor 104 is attached at one of its ends to the other end of gear assembly 134, which servomotor `1041 drives reduction gear assembly 134 through a mechanical coupling not shown. Servomotor 104 has a servomotor shaft 136 projecting from its other end. A portion of shaft 136 is disposed between and in sliding engagement with a pair of upstanding resilient -members 138, 138 fixed to frame 30 and held together in a spaced relationship to apply friction forces to shaft 136 t0 suitably damp operation of servomotor 104` to obviate tendencies of the servo mechanism to hun-t. Reduction gear assembly 134 has an output shaft 140 projecting from its other end, in a direction toward clockmotor shaft 30 and in axial alignment therewith. Prior to missile launching, gear assembly output shaft 140 and clockmotor shaft 32 are rotatably coupled by a `magnetic clutch device i142 so that the aforesaid components of the servo mechanism constitute a closed servo loop and in accordance with lwelll known servo mechanism principles servomotor 104 continuously and automatically maintains wiper arm 112 at a position on resistance element whereat the error signal generated by the error sensing network is zero, thereby mainstud is slideably disposed in a corresponding aperture 174 formed in housing 164 communicating between end surface 166 and an opposite surface 176. The other end of each stud projects from surface 166, each such end being fixed to disk 168. The collared end of each stud projects from surface 176. A helical compression spring 178 is mounted on each such collated end between surface 176 and cap 172 resiliently urging disk 168 against surface 166. When solenoid coil 154 is excited by a suitable electrical current transmitted to terminals 158, 160, disk 168 moves into an abutting relationship against surface 150 of housing 148 in response to magnetic forces generated by solenoid coil 154, and is held in such position with suliicient force to provide a frictionally engaging relationship between disk 168 and surface 150, rotatably coupling armature assembly 144 and solenoid assembly 146, and in turn coupling reduction gear assembly output shaft 140 and clockmotor shaft 30, completing the servo loop as aforesaid. When transmission of the current to terminals 158, 160 is terminated disk 168 returns to its position against surface-166 of housing 164 in response to urging of springs 178 disconnecting such shafts.

Magnetic clutch device 142 is operated to couple the aforesaid shafts prior to missile launching and to decouple them at the instant the missile is launched by an electrical circuit comprising a power source 184 disposed in ship 14, which is connected to terminals 158, 160 of the magnetic clutch device through leads 186, 186 which extend through breakaway connector 22. As long as the multiple socket member 24 remains attached to multiple prong member 26, electric current flows through the magnetic device causing it to couple the shafts. At the instant the missile is launched such members separate, terminating the current ilow and decoupling the shafts, removing all external forces from clockmotor shaft 32, including inertial -forces produced by servomotor 104 and reduction gear assembly 134, and thereby permitting the clockmotor shaft to rotate toward its reference position in response to the bias eiect of the clockmotor mechanism.

Explosive element 18 is fired in response to a iiring circuit comprising explosive element 18, a power source 188, switch device 74, and a normally open acceleration switch 190 which is adapted to close in response to the acceleration effect associated with missile launching, such as, for example, the acceleration switch disclosed in copending patent application Serial No. 372,409, filed August 4, 1953, all connected in series and all disposed in the missile. When switches 74 and 190 are both closed power source 188 res explosive element 18.

In the operation of the apparatus, prior to missile launching, magnetic clutch device 142 is energized through breakaway connector assembly 22 and rotatably couples reduction gear output shaft 140 and clockmotor shaft 30', rendering the servo mechanism effective to maintain clockmotor shaft 30 at the aforesaid position in accordance with the re control device against the biasing eiect of the clockmotor mechanism. Upon missile launching the breakaway connector assembly ceases to transmit energy to magnetic clutch device 142, disconnecting gear assembly output shaft 140 and clockmotor shaft 30, whereupon the clockmotor mechanism drives clockmotor shaft 30 toward its reference circuit closing position at the predetermined rate of rotation. The acceleration effects associated with missile launching close switch 190 shortly after launching, and upon lapse of the interval of time in accordance with the order signal generated by `iire control device 16 switch 74 will close in response to iinal movement of clockmotor shaft 30 to its reference switch closing position, firing explosive element 18.

From the above it will be apparent that the present invention is eiective to provide apparatus for initiating an event in a missile upon lapse of a definite interval of time after missile launching with which such interval of time may be selectively varied as desired up to the instant the missile is launched, and to provide such apparatus with which lthe interval of time may be automatically varied by a tire control device disposed in a location remote from the missile. Exhaustive tests have shown the above described apparatus capable of providing a desired interval between missile launching and initiation of an event in the missile with accuracies within plus or minus-0.1 second. It is further apparent that the apparatus incorporates simple easy to manufacture parts, such as, the clockmotor mechanism and the potentiometer assemblies.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

l. Apparatus for initiating an event in a missile upon lapse of a `definite interval of time after the missile is launched from a launcher in accordance with an order signal for controlling such interval of time generated by a iire control device disposed in a location remote from said missile and in which apparatus a breakaway electrical connecting device provides electrical communication between said missile and said launcher prior to missile launching, which communication is severed the instant the missile is launched, comprising; a clockmotor mechanism carried by said missile and having a rotatable clockmotor shaft having a reference position, said clockmotor shaft being positionable relative to said reference position in response to forces applied thereto, said clockmotor mechanism being adapted to bias said clockmotor shaft to rotate toward said reference position at a predetermined rate of rotation; servo mechanism means comprising an error sensing network including a first sensing element operatively connected to said fire control means and responsive to said order signal disposed in a location remote from said missile, and a second sensing element responsive to the position of said clockmotor shaft carried by said missile and connected in said network through said breakaway connecting device, said error sensing network being adapted to generate an error signal in accordance with the departure of the actual position of said clockmotor shaft from a position whereat it would rotate to its reference position in an interval of time in accordance with said order signal in response to bias of the clockmotor mechanism, amplier means for converting said error signal to a servomotor energizing signal disposed in a location remote from said missile, a servomotor device having a rotatable servomotor device output shaft carried by said missile and electrically connected to said amplilier means through said breakaway connecting device, said servomotor device being adapted to apply positioning forces to said clockmotor shaft to maintain it at the aforesaid position in accordance with the order signal; an electrically controlled clutch device carried by said missile, said clutch device being adapted to rotatably couple said shafts when a suitable electric signal is transmitted thereto and to disconnect said shafts when transmission of said signal is terminated; circuit means for controlling said clutch device electrically connected to said clutch device and adapted to transmit an electrical signal for causing said clutch device to rotatably couple said shafts prior to missile launching and to terminate transmission of such electrical signal at the instant the missile is launched; and means for initiating the event in response to movement of said clockmotor shaft to its reference position carried by said missile.

2. Apparatus in accordance with claim 1 wherein said re control means for controlling the interval of time between the instant the missile is launched and the initiation of an event in the missile is of the type which generates a continuously varying signal and wherein said servomechanism means is adapted to automatically position said clockmotor shaft in response to said order signal.

3. Apparatus in accordance with claim 1 wherein circuit means for controlling said clutch device includes source means for generating said electrical signal for causing said clutch device to rotatively couple said shafts disposed in a location remote from said missile and includes electric leads connecting said source means to said clutch device, said electric leads electrically communicating through said breakaway connecting device.

4. Apparatus in accordance with claim 1 wherein said rst sensing element of the error sensing network is a rotary potentiometer having a rotatable wiper arm operatively connected to said lire control means and wherein said second sensing element of the error sensing network is a rotary potentiometer having a wiper arm mechanically coupled to said clockmotor.

5. Apparatus in accordance with claim 1 wherein said clockwise mechanism includes resilient means adapted to urge said clockmotor shaft to rotate in a given direction, an escapement device adapted to govern the rate of rotation of said clockmotor shaft, and a friction clutch operatively connecting said clockmotor shaft and said escapement device, said friction clutch device being adapted to slip when said servomotor device applies a force in excess of a predetermined magnitude to said clockmotor shaft against the retarding elfects of said escapement device.

6. Apparatus in accordance with claim 1 wherein said means for initiating the event includes an electric circuit, said electric circuit having a switch device mechanically connected to said clockmotor shaft and actuable in response to final movement of said clockmotor shaft to its reference position.

7. Apparatus in accordance with claim 6 wherein said electric circuit includes an acceleration responsive switch device actuable in response to predetermined acceleration effects associated with a normal launching of said missile connected in series with said switch device.

8. In a timer device, the combination comprising; a rotatable shaft, an electric contact rotatable with said shaft and having a reference position, a spring for urging said shaft for rotation toward said reference position, a clockwork mechanism adapted to govern the rate of shaft rotation against the urge of said spring, a servo-motor, and a disconnectible clutch interposed between said servornotor and said shaft and connecting the servo-motor to said shaft for restraining said shaft against movement under urge of said spring and for rotating the shaft in either of opposite directions of rotation to predetermined positions, a slip clutch operatively connecting said shaft to said clockwork mechanism for permitting said servomotor to rotate said shaft independent of said clockwork mechanism, whereby said electric contact may be moved between various angular positions away from said reference position, and means for disconnecting said disconnectible clutch to initiate timing movement of said shaft under urge of the spring and to permit the spring and clockwork to operate independent of inertia of the servomotor when said electric contact is a desired position away from said reference position, the construction and arrangement being such that said spring and said clock- Work mechanism may return said electric contact to said reference position in a preselected interval of time after said disconnectible clutch has been disconnected.

9. Apparatus in accordance with claim 8 including a potentiometer rotatable with said shaft adapted 'to cooperate with a second remotely disposed potentiometer to provide an error signal for driving said reversible servomotor in accordance with the position of said second potentiometer.

10. Apparatus in accordance with claim 8 wherein said timer device is carried by a missile to be launched from launching apparatus of type having a breakaway electrical connector providing electrical connection between the missile and launching apparatus prior to launching, said disconnectible clutch being of the electrically controlled type, said means for disconnecting comprising said breakaway connector adapted to sever electrical communication between the said launching apparatus and the disconnectible clutch upon launching of the missile.

References Cited in the file of this patent UNITED STATES PATENTS 2,444,813 Cunningham July 6, 1948 2,958,282 Czajkowski et al. Nov. 1, 1960 3,004,506 Cooke et al. Oct. 17, 1961 

